Sports Drinks & Magnesium: The Unsung Hero

This is part I in a four-part discussion of Sports Drinks ingredients. This discussion will be limited to Sports Drinks designed for during workouts or events that last less than 1 hour. It will be entirely concerned with the actual evidence in the research on sports drinks and their components, and not what a magazine advertisement or pro-Triathlete or coach thinks are best.
There are many products out there that claim to be beneficial for athletic performance and/or recovery. A major group of products that get a lot of attention and advertising dollars are sports drinks. It seems that every third or fourth commercial is for some energy enhancing drink or drink mix. I can think of at least 6 different sports drinks that I have seen in the last year claiming to be the best product on the market for rehydration, performance, or recovery. All advertising and exercise fads aside, the ingredients are the best measure of how well a product will deliver on the claims that are made.
There has been a great deal of discussion on glucose levels, osmolality (fancy word for amount of solids in a fluid), and inclusion of protein. There are many different opinions, and almost as many valid research articles out there. But I have not seen much (and I am always keeping my eyes open for) discussion about the levels and type of magnesium in Sports Drinks designed for during exercise.
If we look back to the basic science classes in High School and College all the way up to the latest valid research being done, the overwhelming consensus is that without adequate magnesium in the bloodstream, organs, and muscles, performance is significantly impaired. Magnesium is a crucial cofactor in over 300 enzymatic processes that occur within the body. This includes its vital role in musculoskeletal performance and recovery. Without magnesium a whole myriad of ill effects on the musculoskeletal system occur ranging from cramping to weakness to lack of performance.
A review of the ingredients on most Sports Drinks reveals shamefully low levels of magnesium. The typical range is somewhere between 5 and 60 mg. This is known as “window dressing” ingredients for the sake of marketability. The manufacturer claims to have magnesium and can promote as such, but in reality this low level of magnesium makes it virtually a waste of effort on the manufacturer’s part. They might as well not even bother.
In the research, the studied levels have been in the range of 100 to 500 mg. There has been significant evidence to indicate that supplementation, especially during the event, with magnesium results in longer time to exhaustion and enhanced recovery. Granted there have been mixed results, which requires discussion of another point, the type of magnesium used.
No matter how much magnesium, or any other ingredient, we pump into our body we will not get any effect unless it can be effectively absorbed and then utilized. It is well known within the nutritional expert’s community that different form of vitamins and minerals are absorbed and utilized differently. Depending on the form of the vitamin or mineral it may or may not produce beneficial or deleterious effects. Looking at the ingredient list of many Sports Drinks and supplements, the most common form of magnesium that is found is Magnesium Oxide. This is a form that has a significantly limited bioavailability (the measure of how well the body absorbs and utilizes the ingredient) in humans. It is a cheap form of magnesium and therefore can be sprinkled into Sports Drinks with little danger of affecting the profit margin for the manufacturer. So, it is true that you are getting magnesium into your body, but the truth is that you are not effectively utilizing it.
It appears that this is a major reason that the research is mixed on the results obtained with magnesium supplementation. The effects depended upon the type of magnesium used. Most articles are hazy on what form of magnesium they used.
A form of magnesium that has a high bioavailability is Magnesium Glycinate. It is found in the more expensive supplements that quality Naturopaths, Nutritionists, and Sports Chiropractors like I prescribe to our patients. The high utilization ensures a high degree of confidence that the magnesium is not just producing expensive urine. I can see no value in supplementing the toilet with magnesium to improve my exercise performance. With this form the amount can be lower because more is actually be utilized than other forms so less is needed which means less expense while still getting better utilization by the body.
Take a look at your Sports Drink that you have in your cupboard or that you are buying at the store. Does it even contain magnesium? How much? What form?
If you cannot find the specific amount or form in the ingredients list, the best resource is the Internet. Most manufacturers have a website that lists the ingredients in their products.

-DrTri

References:

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